robinson



D. P. ROBIN-SON.

METHOD OF HERMETICALLY ATTACHING CAN ENDS T0 CAN BODIES.

APPLICATION FILED ,OCT. 3,1918.

Patented Sept. 6,1921.

2 SHEETS-SHEET I.

D. P. ROBINSON.

METHOD OF HERMETICALLY ATTACHING CAN ENDS T0 CAN BODIES.

APPLICATION FILED OCT. 3,1918.

PatentedSept. 6,1921.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

DANIEL P. ROBINSON, 0F BALTIMORE, MARYLAND, ASSIGNOR TO CONTINENTAL CAN COMPANY, INC., OF SYRACUSE, NEW YORK, A CORPORATION OF NEW YOR METHOD OF HERMETICALLY ATTACHING CAN-ENDS TO CAN-BODIES.

Specification of Letters Patent.

Application filed October 3, 1918 Serial No. 256,733.

To all whom it may concern.-

Be it known that I, DANIEL P. ROBINSON, a citizen of the United States, residing at Baltimore, State of lilaryl and, have invented certain new and useful Improve: ments in Methods of Hermetically Attaching Can-Ends toCan-Bodies, of which the following is a description, reference being had to the accompanying drawing and to the form a hermetic seam joining the end to the can body. A gasket or sealing material is usually employed in making the oint tight. In forming the flange on the can body the metal is drawn to a more or less extent and it sometimes happens that the extreme edge of the flange splits through this drawing action. It also sometimes happens that the joined side edges at the side seam, where they extend into the flange, will split or open and whenever a flange has a split therein from any one of the above causes, a leak is liable to occur when this flange is formed into the double seam.

An object of the present invention is to provide a method of attaching can ends to can bodies which includes the healing or closing of all splits in the edges of the flange or at the side sea-ms prior to the rolling of the flange into the double seam.

In the drawings- Figure 1 is; a view in vertical section, showing a portion of the can body with a flange formed thereon preparatory to the joining of an end to a canbody by'a double seam;

Fig. 2

Fig. 3 is an enlarged in the flange;

Fig. 4 is an enlarged end view, showing a split at the side seam;

Fig. 5 is an enlarged view, showing the is an end view'of the same;

View, showing a split flange coated with solder at the edge and the split formed therein cured or closed by the solder; Fig. 6 is a view showing more or less diagrannnatically, the double seam for joinin the can end to the can body; I I

Fig. 7 is a view showing more-or less diagrammatically an apparatus for applyin the solder to the flange of the can body. 6 In i'orn ing c'ylindrical cansit is a common practice to cut a metal blank to proper size and then bring the side edges of the blank together and then overlap or interlock the side edges, thus forming a cylinder which serves as the body of the can. In Figs. 1 and 2 of the drawings, I have shown a can body at 1, in which the side edges, indicated at 22, are overlapped and soldered or otherwise secured. After the cylindrical body portion has been formed, then both endsof the can body are 'iianged-that is, the metal of the can body is turned 0ntwardly and expanded by means of dies or rolls, so as to form a laterally extending flange. The flange at one end 0f the can body is indicated at 3 in Fig. 3 of the drawings. In the forming of this flange the metal is caused to flow or is drawn to a certain extent so as to produce the flange. It sometimes happens that the metal, owing to this strain thereon, splits; the split runs from the edge more orless into the flange; The metal at the extreme ends of the'edges which overlap to form the side seam is usually cut away to a'certain extent so as to avoid too great a bulk of metal where the side seam is rolled into the double seam joining the can end to the can body] The forming of the flange also sometimes strains the metal .at the side seam so that a. split or opening'of the sideseam occurs atthe extreme edge of the flange. In F igs. 2 and 3 of the drawings, I have indicated at l, a split formed in the flange in the manner above described. In Fig. 4 of the drawings, I have indicated a split at formed at the side seam. The can end is secured to'the can body by rolling the curled outer edge of the can end.

Patented Sept. 6, 1921.

into a double seam with the flange onthe can split in the flange, either in the side seam or throughout the extent of the flange, is

.completely healed or closed before the double seam is formed. I prefer to heal or close this split by the use of solder. In Fig. 7 of the. drawings, I have shown one form of apparatus for carrying out this step in the method. The apparatus consists of a solder tank 9, having solder 10 therein which is kept in a molten condition. Rotating in the solder bath is a cylindrical roll 11, which turns in a clockwise direction. -Also, rotating in the bath is a cylindricalroll 12, which turns in a counter-clockwise direction. These rolls are so disposed in the molten solder that the upper portions of the rolls only extend above the surface of the solder. As the rolls rotate a film of solder will be taken up thereby. Stripper plates 13 may be used with the rolls for determining the thickness of the film of solder and evenly distributing the same, if desired. The can body, indicated at 1, with a flange at each end thereof, is rotated on its axis and thus rolled lengthwise of the rolls l1 and 12. Guides 14 may be used for directing the can body and the can body may be driven along the rolls by an endless chain 15. It will be readily seen that, as the can body rolls along these solder rolls, the flanges 3 on the can body will be coated on their under faces with solder and this solder will particularly run into the split completely filling the same and joining the edges of the split. It will also oin the split at the side seam, if the same is open to any extent. After the can is rolled along the solder rolls, all the splits in the'flanges willbe completely healed or closed. It is understood, of course, that the can body will roll along the rolls in a flux bath before they reach thesolder rolls, so

that the flange will be'fluxed before the 1 is rolled into a double seam with the can end in the usual manner, a gasket or non-metallic sealing material of some character being used in order that the joint will be perfectly hermetic.

Seams of the above character are particularly desirable where the contents of the can is to be kept as far as possible from any contact with the solder. By coating the under face of the flange, I place the solder at a point where it is far removed from the interior of the can and where the seam is formed the solder is not exposed to contact with the material in the can.

While I have described my method as particularly adapted for closing splits in round or cylindrical cans, it is obvious that the invention may be equally applied to other shapes of can bodies. In the forming of a square can, the corner of the can is usually rounded and in turning the flange the metal is drawn at the corner some time resulting in'the splitting of the metal. My improved method could be well applied to cans of this character and could be applied in the same manner as above described. The form of the apparatus, possibly, for carrying out the method may require some changes, but any suitable apparatus may be employed for applying the solder to the flange on the can body.

It is obvious that minor changes in the details of steps of the method described may be made without departing from the spirit of the invention as set forth in the-appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. The method of hermetically attaching can ends to can bodies, comprising forming a flange on the can body, applying solder to the flange for closing all slits near the edge thereof, placing 'a non-metallic sealing material between the can end and the flange on the can body, subsequently formingthe flange on the can body and the edge of the 

